Pulse and Glide Cruise Control for Fuel Economy
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Solution Overview
Problem
Existing vehicle speed control systems are not optimized for fuel economy or emissions, as they tend to over-throttle on upgrades and retard on downgrades, wasting energy and operating the engine away from its optimal brake specific fuel consumption (BSFC) point, even when traversing varying road gradients.
Innovation Solution
Implementing a pulse and glide phase control method during cruise control, where engine torque is applied responsive to engine speed during pulse phases and engine combustion is discontinued during glide phases, maintaining a mean speed equivalent to a desired threshold while reducing fuel consumption and noise, vibration, and harshness (NVH) effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional cruise control maintains constant speed by continuous throttle application, then vehicle speed stability is improved, but fuel consumption increases and engine operates away from optimal BSFC point
Solution Approach 1:
The patent implements periodic acceleration and coasting phases instead of continuous throttle application. The controller alternates between applying torque to accelerate the vehicle and discontinuing torque application to allow coasting, creating a periodic control pattern that reduces fuel consumption while maintaining average speed near the target value.
Solution Approach 2:
The patent transitions from static constant-speed control to dynamic speed control where the vehicle speed varies within a range around the target speed. The controller dynamically adjusts torque application based on current speed, creating a dynamic control strategy that allows speed fluctuations to optimize fuel efficiency.
2Stability of the object's composition
If cruise control over-throttles on upgrades to maintain speed, then speed stability is improved, but energy waste increases
Solution Approach 1:
The patent applies partial throttle action only when necessary during coasting phases, rather than continuous full throttle application. The controller selectively applies torque during specific intervals (coasting phases) rather than maintaining constant throttle, reducing overall energy waste while still achieving speed maintenance over varying road gradients.
3Ease of operation
If engine operates at constant throttle position, then control simplicity is improved, but BSFC optimization is reduced
Solution Approach 1:
The patent implements dynamic throttle control that varies the throttle position between fully closed (during acceleration phases) and partially open (during coasting phases), rather than maintaining a constant throttle position. This dynamic adjustment allows the engine to operate at optimal BSFC points during coasting while simplifying overall control through automated phase management.
Data Source
AI summary
The present disclosure describes systems and methods for controlling the speed of a vehicle comprising: during a pulse phase of cruise control, applying engine torque to raise speed, the amount and duration of which being responsive to engine speed; and during a glide phase of cruise control, discontinuing engine combustion. In this way cruise control may maintain a mean speed equivalent to a desired, threshold speed while reducing fuel consumption, and NVH effects felt by the end user compared to traditional cruise control methods.